Important Questions Class 7 Science Chapter 9

Important Questions Class 7 Science Chapter 9 – Soil

Science is a foundational subject for students who would pursue science-oriented streams such as engineering, medical, architecture, and many others. Today’s world is surrounded by a lot of science-oriented developments, so along with academic understanding for passing the exams, the various applications of science would be very important for students to live their regular lives.

Chapter 9 of Class 7 Science is about “Soil”. The chapter starts by explaining the topic of different soil profiles. Below are the total topics covered in this chapter:

• Various layers of soil
• Types of soil
• Properties and characteristics of soil
• Role of moisture in the soil
• Soil and crops

Extramarks is a leading online learning platform, trusted by many students and teachers across the country. Students can visit the Extramarks website to access our comprehensive suite of study materials, including NCERT solutions, CBSE sample papers, revision notes, etc. These study notes were created by our team of science expert teachers using the most recent CBSE curriculum.

Class 7 Science starts to become challenging, and the complexity of various chapters requires a proper understanding of concepts and continuous revision. At Extramarks, our team understands the importance of regularly solving exam-oriented questions. Students can refer to our question bank, Important Questions Class 7 Science Chapter 9, which consists of various difficulty-level questions from sources such as NCERT textbooks, exemplar books, past year question papers, reference books, etc.

Solving Important Questions Class 7 Science Chapter 9 allows students to ensure whether they have covered the topic altogether or not. If students have missed something, they can learn it while solving the questions from our Science Class 7 Chapter 9 Important Questions study material.

Important Questions Class 7 Science Chapter 9 – With Solutions

To have a good understanding of various science topics, it’s essential for students to revise and practise solving a lot of questions regularly. Students can refer to the question bank from the Extramarks team. These questions are carefully curated, keeping in mind the CBSE exam and syllabus guidelines. Our expert team of science teachers have prepared step-by-step instructions for all these questions for students to understand the concepts covered in each solution quickly. 

An important tip while solving the Chapter 9 Class 7 Science Important Questions is to analyse the format for writing and understanding the concept, which will help them to remember the concept more simply and efficiently. 

To get a good exam score, students must practise their writing skills to enhance their understanding  during exams and give equal attention to using diagrams and illustrations to score more marks. 

Below we have given a few sets of questions from our Important Questions Class 7 Science Chapter 9 for students to get familiar with the nature of questions covered in our question and answer bank.

Question 1. Explain how soil is formed.

Answer 1: The soil is formed by a process called weathering of rocks. Weathering refers to the process of breaking down the soil by many factors which break down huge rocks i.e,. physical breakdown and chemical decomposition of minerals by wind, water, and climatic changes. Weathering of rocks converts big pieces of rock into smaller pieces, eventually forming soil.

Question 2. List the differences between clayey soil and sandy soil.

Answer 2: 

Question 3: Explain how soil pollution and soil erosion could be prevented.

Answer 3:

Soil pollution can be kept under control by the following measures:

1. We can reduce soil pollution by reducing the use of plastics, as they take a longer time to decompose, leading the soil to lose its nutrients.
2. We can control soil pollution by using pesticides and fertilisers in a controlled method.

Soil erosion can be kept under control by taking the following steps:

1. Planting more trees will result in a reduction in soil erosion as trees help bind the soil particles.
2. By stopping deforestation and avoiding overgrazing by the cattle.

Question 4: How can a farmer convert acidic soil to neutral soil?

Answer 4: A farmer can convert acidic soil into neutral soil by adding a small quantity of slaked lime or quicklime to neutralise the acidic nature of the soil.

Question 5: Continuously waterlogged soils are disadvantageous for plant growth. Why?

Answer 5: In waterlogged soil, the air bubble present in between soil particles is accumulated by the water particles, pushing the oxygen out into the atmosphere. The plant’s roots do not get the oxygen required for survival; hence water-logged soils are disadvantageous for plant growth.

Question 6. Gardeners gently dig up the soil around the roots of garden herbs (plants) frequently. Give reasons.

Answer 6: Gardens gently dig soil around the roots of garden herbs for the following reasons:

1. For easier percolation of water into the soil.
2. To provide easier growth for the root.
3. For removing weeds.
4. For aerating the soil.

Question 7. Is it good practice to remove grass and small plants that are growing in an open, unused field? Give a reason to support your answer.

Answer 7: It is not good practice to remove grass and small plants from new fields as the roots of the grass bind loose soil particles, which prevents the washout of the top layer of soil from strong winds. To prevent soil erosion and wash out important nutrients for plant growth and maintain the soil’s nutritional value, the tiny plants and grass shouldn’t be removed from unused fields. 

Question 8. What do you mean by the percolation rate of the soil?

Answer 8: The passage of water seeping through the soil is called percolation, and the rate at which water seeps into the soil with respect to time is called the percolation rate of the soil. The highest rate of percolation is in sandy soil, and the lowest percolation rate is found in clayey soil.

Question 9. What is meant by water retention in the soil?

Answer 9: The amount of water retained by the soil after percolation is defined as the water retention of the soil. The quantity of water retained by the soil is the water provided to the plants and other organisms living in the soil.

Question 10. Define soil and various factors affecting the soil.

Answer 10: The soil is the crust part of the earth. Soil is a heterogeneous mixture of rock particles, minerals and humus. Various factors affect soil structure and composition, including temperature, light, humidity, wind, and rainfall.

Question 11. Water holding capacity is highest in:

1. Sandy soil
2. Clayey soil
3. Loamy soil
4. A mixture of sandy and loamy soil

Answer11: Clayey soil

Question 12. How is clayey soil useful for crops?

Answer 12: Clayey soil has the property of retaining water, which is extremely helpful in growing crops. The amount of organic material and humus is also greater in clayey soils as crops require a regular water supply to grow. Clayey soil with a low percolation rate and high water holding capacity is ideal for growing crops.

Question 13. Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40 min. for 200 mL of water to percolate through the soil sample. Calculate the rate of percolation.

Answer 13: The rate of percolation is the amount of water that seeps into the soil in a given amount of time, for example, 200 ml/400 min = 5 ml/min.

Question 14. What is the soil profile?

 Answer 14: Various vertical sections present in soil layers are known as soil profiles.

Each layer has its characteristic depth, colour, chemical composition, and texture.

Question 15. What do different soil colours indicate?

Answer 15: The colour of the soil ranges from red to black. The colour of soil depends on the number of minerals and organic materials in the soil. Red soil indicates a high amount of iron, whereas black soil represents a high amount of organic material. The white colour of the soil shows that the soil is bleached of its nutrients.

Question 16:  Why is soil erosion relatively less in dense forests as compared to barren, open fields?

Answer 16: In a dense forest, the thick canopy and the roots of the tree bind soil particles and decrease the effect of rainfall, preventing soil erosion. In open barren lands, the soil is exposed to rainfall, and the soil becomes loose and gets carried away, eroding topsoil and minerals.

Question 17: In towns and cities, generally,  bore wells have to be dug very deep to get water as compared to bore wells dug in villages. Give suitable reasons.

Answers 17: In cities and towns, generally,  bore wells should be dug very deep to get water in comparison to bore wells dug in villages. It is so for the following reasons :

(i) Excessive use of water in cities and towns depletes the groundwater  levels, resulting in decreased groundwater.

(ii) Cities have asphalted roads, and vast regions of soil are concreted. As a result, rainwater can’t percolate to recharge groundwater, and the groundwater stage addition decreases.

 Villages have large regions of open soil floor and fewer asphalted roads, thus allowing the water to percolate into the soil and increase the groundwater level.

Question 18: Why are earthworms called the farmer’s friends?

Answer 18: Earthworms are called farmer’s friends as they burrow the soil, thus making the soil more porous. Porosity in the soil helps in the aeration of the soil, thus increasing the plantation of the soil. They also help in managing biodiversity, and they break organic matter into smaller pieces so that plants can take them up. Their casting is also used as fertiliser for the plants.

Benefits of Solving Important Questions Class 7 Science Chapter 9

Science is a conceptual subject. For students to have a strong hold on the subject, they must have a clear understanding of the topic and practise as many questions as possible to enhance their skills. Extramarks are an excellent choice for students desiring to get good grades in exams. Along with Important Questions Class, 7 Science Chapter 9 Extramarks also provides CBSE Revision Notes for complete preparation for exams.

To feel confident in their preparation for taking the exams, students are advised to practise the Important Questions Class 7 Science Questions Chapter 9. The Important Questions Science Questions in Chapter 9 cover all the important topics. These important questions are created from an exam perspective and are more likely to come in the CBSE examination. Solving important questions gives students a competitive advantage.

These are the benefits of studying Important Questions Class 7 Science Chapter 9:

1. Questions from each topic in the chapter are taken from our question bank. So, while solving the questions, students will get to self-assess their knowledge of various topics in the chapter.  So, by solving the questions, students will get to revise everything and cover the entire syllabus. 
2. Important Questions Class 7 Science Chapter 9 is a group of questions created by subject experts exclusively for exams. There is a higher likelihood that some of these questions will be asked on the exam. Thus, it gives students an overview of how questions might appear on their exams and helps them prepare.
3. Our expert team of Mathematics teachers has prepared step-by-step solutions for each question. It provides a deep understanding of concepts and helps students prepare for their exams in a balanced way.
4. Class 7 Science Chapter 9 Important Questions consist of different formats of questions, including MCQs, short answers and long answer questions. Students can choose from multiple types based on their exam needs.

Extramarks is one of the leading online learning platforms that offer complete study materials. Students can refer to other study materials available on our Extramarks’ website. Students can click on the links below to access the most relevant resources: 

• NCERT books
• CBSE Revision Notes
• CBSE syllabus
• CBSE sample papers
• CBSE past  years’ question papers
• Important formulas 
• CBSE extra questions